Note: Some software, like Advanced SystemCare with Surfing Protection, can protect files in the Firefox profile folder against changes. If you have such software then check the settings or uninstall this software.

https://support.mozilla.org/en-US/kb/how-to-fix-preferences-wont-save
'''Note:''' Some software, '''like''' Advanced SystemCare with Surfing Protection, can protect files in the Firefox profile folder against changes. If you have such software then check the settings or uninstall this software.

Spørgsmålsstiller

Thanks for the suggestions, but none have worked. I am using the very latest FireFox version (66.0.1). The theme was recently updated. Although I do use Advanced System Care, I set it so it does NOT automatically load at boot, so it is inactive.

Interestingly, I noticed that when FireFox loads, initially the desired add-on theme is active, but just a few seconds into the loading process, it changes to the default.

'Tis a puzzlement!

Thanks for the suggestions, but none have worked. I am using the very latest FireFox version (66.0.1). The theme was recently updated. Although I do use Advanced System Care, I set it so it does NOT automatically load at boot, so it is inactive.
Interestingly, I noticed that when FireFox loads, initially the desired add-on theme is active, but just a few seconds into the loading process, it changes to the default.
'Tis a puzzlement!

. . . using the very latest FireFox version (66.0.1).The theme was recently updated

Check with the theme's support.

when FireFox loads, initially the desired add-on theme is active

Type about:support in the address bar and press Enter.
Under the main banner, press the button; Copy Text To Clipboard..
Now in the Reply Box on the forum page,
do a right-click in the box and select Paste.

This will show us your system details.
No Personal Information Is Collected.

''BKSmith714 [[#answer-1207774|said]]''
<blockquote>
. . . using the very latest FireFox version (66.0.1).<br>The theme was recently updated
</blockquote>
Check with the theme's support.
<blockquote>
when FireFox loads, initially the desired add-on theme is active
</blockquote>
Type '''about:support''' in the address bar and press '''Enter.'''
Under the main banner, press the button; '''Copy Text To Clipboard.'''.
Now in the Reply Box on the forum page,
do a right-click in the box and select '''Paste.'''
This will show us your system details.
'''No Personal Information Is Collected.'''

Note: Some software, like Advanced SystemCare with Surfing Protection, can protect files in the Firefox profile folder against changes. If you have such software then check the settings or uninstall this software.

https://support.mozilla.org/en-US/kb/how-to-fix-preferences-wont-save
'''Note:''' Some software, '''like''' Advanced SystemCare with Surfing Protection, can protect files in the Firefox profile folder against changes. If you have such software then check the settings or uninstall this software.

I just fixed it by disabling another addon (which I didn't check if you have but if someone runs into this, I want them to find what worked for me) which gives you a dark interface while keeping the Windows dynamic color for your tab-bar and some other interface elements. it was called "Native Dark" - it appears to have fixed my issue.

I just fixed it by disabling another addon (which I didn't check if you have but if someone runs into this, I want them to find what worked for me) which gives you a dark interface while keeping the Windows dynamic color for your tab-bar and some other interface elements. it was called "Native Dark" - it appears to have fixed my issue.